feat: allow collab and force close DLC channel

CHANGELOG.md

@@ -10,8 +10,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Chore: move telegram link into toplevel of settings so that it can be found easier
 - Feat: update coordinator API to show more details on pending channel balance
 - Feat: show dlc-channel balance instead of ln-balance in app and in coordinator's API
+- Feat: allow collaboratively close a channel from coordinator and the app
 - Chore: don't allow multiple dlc-channels per user
 - Feat: show dlc-channel opening transaction in transaction history
+- Feat: allow force-close a DLC channel
 
 ## [1.7.4] - 2023-12-20
 

coordinator/src/admin.rs

@@ -1,6 +1,7 @@
 use crate::collaborative_revert;
 use crate::db;
 use crate::parse_channel_id;
+use crate::parse_dlc_channel_id;
 use crate::routes::AppState;
 use crate::AppError;
 use anyhow::Context;
@@ -492,15 +493,16 @@ pub async fn close_channel(
     Query(params): Query<CloseChannelParams>,
     State(state): State<Arc<AppState>>,
 ) -> Result<(), AppError> {
-    let channel_id = parse_channel_id(&channel_id_string)
+    let channel_id = parse_dlc_channel_id(&channel_id_string)
         .map_err(|_| AppError::BadRequest("Provided channel ID was invalid".to_string()))?;
 
     tracing::info!(channel_id = %channel_id_string, "Attempting to close channel");
 
     state
         .node
         .inner
-        .close_channel(channel_id, params.force.unwrap_or_default())
+        .close_dlc_channel(channel_id, params.force.unwrap_or_default())
+        .await
         .map_err(|e| AppError::InternalServerError(format!("{e:#}")))?;
 
     Ok(())

coordinator/src/lib.rs

@@ -8,6 +8,8 @@ use diesel::PgConnection;
 use diesel_migrations::embed_migrations;
 use diesel_migrations::EmbeddedMigrations;
 use diesel_migrations::MigrationHarness;
+use dlc_manager::DlcChannelId;
+use hex::FromHex;
 use lightning::ln::ChannelId;
 use rust_decimal::prelude::FromPrimitive;
 use rust_decimal::prelude::ToPrimitive;
@@ -91,6 +93,10 @@ pub fn parse_channel_id(channel_id: &str) -> Result<ChannelId> {
     Ok(ChannelId(channel_id))
 }
 
+pub fn parse_dlc_channel_id(channel_id: &str) -> Result<DlcChannelId> {
+    Ok(DlcChannelId::from_hex(channel_id)?)
+}
+
 pub fn compute_relative_contracts(contracts: Decimal, direction: &::trade::Direction) -> Decimal {
     match direction {
         ::trade::Direction::Long => contracts,

coordinator/src/node.rs

@@ -688,6 +688,19 @@ impl Node {
             }
         }
 
+        if let Message::Channel(ChannelMessage::CollaborativeCloseOffer(close_offer)) = &msg {
+            let channel_id_hex_string = close_offer.channel_id.to_hex();
+            tracing::info!(
+                channel_id = channel_id_hex_string,
+                node_id = node_id.to_string(),
+                "Received an offer to collaboratively close a channel"
+            );
+
+            // TODO(bonomat): we should verify that the proposed amount is acceptable
+            self.inner
+                .accept_dlc_channel_collaborative_close(close_offer.channel_id)?;
+        }
+
         if let Message::SubChannel(SubChannelMessage::CloseFinalize(msg)) = &msg {
             let mut connection = self.pool.get()?;
             match db::positions::Position::get_position_by_trader(

crates/fund/examples/fund.rs

@@ -53,7 +53,7 @@ async fn fund_everything(faucet: &str, coordinator: &str) -> Result<()> {
     let coordinator_balance = coordinator.get_balance().await?;
     tracing::info!(
         onchain = %Amount::from_sat(coordinator_balance.onchain),
-        offchain = %Amount::from_sat(coordinator_balance.offchain),
+        offchain = %Amount::from_sat(coordinator_balance.dlc_channel),
         "Coordinator balance",
     );
 

crates/ln-dlc-node/src/node/dlc_channel.rs

@@ -158,6 +158,85 @@ impl<S: TenTenOneStorage + 'static, N: LnDlcStorage + Sync + Send + 'static> Nod
         Ok(())
     }
 
+    pub async fn close_dlc_channel(&self, channel_id: DlcChannelId, force: bool) -> Result<()> {
+        let channel_id_hex = hex::encode(channel_id);
+        tracing::info!(channel_id = channel_id_hex, "Closing DLC channel");
+
+        let channel = self
+            .get_dlc_channel(|channel| channel.channel_id == channel_id)?
+            .context("DLC channel to close not found")?;
+
+        if force {
+            self.force_close_dlc_channel(&channel_id)?;
+        } else {
+            self.propose_dlc_channel_collaborative_close(channel)
+                .await?
+        }
+
+        Ok(())
+    }
+
+    fn force_close_dlc_channel(&self, channel_id: &DlcChannelId) -> Result<()> {
+        let channel_id_hex = hex::encode(channel_id);
+
+        tracing::info!(
+            channel_id = %channel_id_hex,
+            "Force closing DLC channel"
+        );
+
+        self.dlc_manager.force_close_channel(channel_id)?;
+        Ok(())
+    }
+
+    /// Collaboratively close a DLC channel on-chain if there is no open position
+    async fn propose_dlc_channel_collaborative_close(&self, channel: SignedChannel) -> Result<()> {
+        let channel_id_hex = hex::encode(channel.channel_id);
+
+        tracing::info!(
+            channel_id = %channel_id_hex,
+            "Closing DLC channel collaboratively"
+        );
+
+        let counterparty = channel.counter_party;
+
+        match channel.state {
+            SignedChannelState::Settled { .. } | SignedChannelState::RenewFinalized { .. } => {
+                spawn_blocking({
+                    let dlc_manager = self.dlc_manager.clone();
+                    let dlc_message_handler = self.dlc_message_handler.clone();
+                    let peer_manager = self.peer_manager.clone();
+                    move || {
+                        let settle_offer = dlc_manager
+                            .offer_collaborative_close(
+                                &channel.channel_id,
+                                channel.counter_params.collateral,
+                            )
+                            .context(
+                                "Could not propose to collaboratively close the dlc channel.",
+                            )?;
+
+                        send_dlc_message(
+                            &dlc_message_handler,
+                            &peer_manager,
+                            counterparty,
+                            Message::Channel(ChannelMessage::CollaborativeCloseOffer(settle_offer)),
+                        );
+
+                        anyhow::Ok(())
+                    }
+                })
+                .await??;
+            }
+            _ => {
+                tracing::error!( state = %channel.state, "Can't collaboratively close a channel with an open position.");
+                bail!("Can't collaboratively close a channel with an open position");
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Collaboratively close a position within a DLC Channel
     pub async fn propose_dlc_channel_collaborative_settlement(
         &self,
         channel_id: DlcChannelId,
@@ -168,7 +247,7 @@ impl<S: TenTenOneStorage + 'static, N: LnDlcStorage + Sync + Send + 'static> Nod
         tracing::info!(
             channel_id = %channel_id_hex,
             %accept_settlement_amount,
-            "Settling DLC channel collaboratively"
+            "Settling DLC in channel collaboratively"
         );
 
         spawn_blocking({
@@ -192,6 +271,17 @@ impl<S: TenTenOneStorage + 'static, N: LnDlcStorage + Sync + Send + 'static> Nod
         .await?
     }
 
+    pub fn accept_dlc_channel_collaborative_close(&self, channel_id: DlcChannelId) -> Result<()> {
+        let channel_id_hex = hex::encode(channel_id);
+
+        tracing::info!(channel_id = %channel_id_hex, "Accepting DLC channel collaborative close offer");
+
+        let dlc_manager = self.dlc_manager.clone();
+        dlc_manager.accept_collaborative_close(&channel_id)?;
+
+        Ok(())
+    }
+
     pub fn accept_dlc_channel_collaborative_settlement(
         &self,
         channel_id: DlcChannelId,

crates/ln-dlc-node/src/tests/dlc_channel.rs

@@ -1,21 +1,154 @@
+use crate::node::InMemoryStore;
 use crate::node::Node;
+use crate::storage::TenTenOneInMemoryStorage;
 use crate::tests::bitcoind::mine;
 use crate::tests::dummy_contract_input;
 use crate::tests::init_tracing;
 use crate::tests::wait_until;
 use bitcoin::Amount;
+use dlc_manager::channel::signed_channel::SignedChannel;
 use dlc_manager::channel::signed_channel::SignedChannelStateType;
 use dlc_manager::contract::Contract;
 use dlc_manager::Storage;
+use std::sync::Arc;
 use std::time::Duration;
 
 #[tokio::test(flavor = "multi_thread")]
 #[ignore]
-async fn vanilla_dlc_channel() {
+async fn can_open_and_collaboratively_close_channel() {
     init_tracing();
 
     // Arrange
+    let (app, coordinator, coordinator_signed_channel, app_signed_channel) =
+        setup_channel_with_position().await;
 
+    let app_on_chain_balance_before_close = app.get_on_chain_balance().unwrap();
+    let coordinator_on_chain_balance_before_close = coordinator.get_on_chain_balance().unwrap();
+
+    tracing::debug!("Proposing to close dlc channel collaboratively");
+
+    coordinator
+        .close_dlc_channel(app_signed_channel.channel_id, false)
+        .await
+        .unwrap();
+
+    wait_until(Duration::from_secs(10), || async {
+        app.process_incoming_messages()?;
+
+        let dlc_channels = app
+            .dlc_manager
+            .get_store()
+            .get_signed_channels(Some(SignedChannelStateType::CollaborativeCloseOffered))?;
+
+        Ok(dlc_channels
+            .iter()
+            .find(|dlc_channel| dlc_channel.counter_party == coordinator.info.pubkey)
+            .cloned())
+    })
+    .await
+    .unwrap();
+
+    tracing::debug!("Accepting collaborative close offer");
+
+    app.accept_dlc_channel_collaborative_close(coordinator_signed_channel.channel_id)
+        .unwrap();
+
+    wait_until(Duration::from_secs(10), || async {
+        mine(1).await.unwrap();
+        coordinator.sync_wallets().await?;
+
+        let coordinator_on_chain_balances_after_close = coordinator.get_on_chain_balance()?;
+
+        let coordinator_balance_changed = coordinator_on_chain_balances_after_close.confirmed
+            > coordinator_on_chain_balance_before_close.confirmed;
+
+        if coordinator_balance_changed {
+            tracing::debug!(
+                old_balance = coordinator_on_chain_balance_before_close.confirmed,
+                new_balance = coordinator_on_chain_balances_after_close.confirmed,
+                "Balance updated"
+            )
+        }
+
+        Ok(coordinator_balance_changed.then_some(true))
+    })
+    .await
+    .unwrap();
+
+    wait_until(Duration::from_secs(10), || async {
+        mine(1).await.unwrap();
+        app.sync_wallets().await?;
+
+        let app_on_chain_balances_after_close = app.get_on_chain_balance()?;
+
+        let app_balance_changed = app_on_chain_balances_after_close.confirmed
+            > app_on_chain_balance_before_close.confirmed;
+        if app_balance_changed {
+            tracing::debug!(
+                old_balance = app_on_chain_balance_before_close.confirmed,
+                new_balance = app_on_chain_balances_after_close.confirmed,
+                "Balance updated"
+            )
+        }
+
+        Ok(app_balance_changed.then_some(()))
+    })
+    .await
+    .unwrap();
+}
+
+#[tokio::test(flavor = "multi_thread")]
+#[ignore]
+async fn can_open_and_force_close_channel() {
+    init_tracing();
+
+    // Arrange
+    let (app, coordinator, coordinator_signed_channel, _) = setup_channel_with_position().await;
+
+    tracing::debug!("Force closing dlc channel");
+
+    wait_until(Duration::from_secs(10), || async {
+        mine(1).await.unwrap();
+
+        let dlc_channels = coordinator
+            .dlc_manager
+            .get_store()
+            .get_signed_channels(None)?;
+        Ok(dlc_channels
+            .iter()
+            .find(|dlc_channel| dlc_channel.counter_party == app.info.pubkey)
+            .cloned())
+    })
+    .await
+    .unwrap();
+
+    coordinator
+        .close_dlc_channel(coordinator_signed_channel.channel_id, true)
+        .await
+        .unwrap();
+
+    wait_until(Duration::from_secs(10), || async {
+        mine(1).await.unwrap();
+
+        let dlc_channels = coordinator
+            .dlc_manager
+            .get_store()
+            .get_signed_channels(None)?;
+        Ok(dlc_channels.is_empty().then_some(()))
+    })
+    .await
+    .unwrap();
+
+    // TODO: we could also test that the DLCs are being spent, but for that we would need a TARDIS
+    // or similar
+}
+
+async fn setup_channel_with_position() -> (
+    Arc<Node<TenTenOneInMemoryStorage, InMemoryStore>>,
+    Arc<Node<TenTenOneInMemoryStorage, InMemoryStore>>,
+    SignedChannel,
+    SignedChannel,
+) {
     let app_dlc_collateral = 10_000;
     let coordinator_dlc_collateral = 10_000;
 
@@ -245,4 +378,10 @@ async fn vanilla_dlc_channel() {
     })
     .await
     .unwrap();
+    (
+        app,
+        coordinator,
+        coordinator_signed_channel,
+        app_signed_channel,
+    )
 }